My buddy Steve has a Go camera. It's been dropped, run over, submerged and hit whilest cycling, skiing and kayaking. He mounts either on top of his helmet or in a chest harness. It's a durable little sucker. Video quality seems good to me. Chest-mounted, it works well, on top of your brain bucket it's pretty tall compared to the bullet form factor IMHO. But no overhanging rocks or trees have broken it, a couple enough to knock him off the bike.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"To live is to suffer, to survive is to find some meaning in the suffering." -- Friedrich Nietzsche